It was not clear why the truck was going the wrong way.
Bits of gift wrap and toys were strewn about the highway, suggesting the minivan was carrying a family heading home from the holidays, Santiago said.
"It was among the worst I've seen," he said of the crash scene.
The infant killed in the crash was about 6 months old, Santiago said. The others killed, a woman and three children, were pronounced dead at the scene, he said.
A man and two other children from the minivan were taken to the hospital with life-threatening injuries, Santiago said. The driver of the pickup also was taken to a hospital, but his injuries did not appear to be as serious, he said.
